Sensors are used to measure or monitor a parameter. Sensors can provide quantitative information on the parameter or how the parameter changes over time. For example, a temperature sensor is commonly used to monitor the operating temperature of a component or a biological entity. The temperature sensor can be used to monitor temperatures over a variety of operating conditions and formats. Typically, sensor data is used in the assessment of an object or to monitor performance in different operational modes and environmental factors. Sensors can trigger an action such as turning off the system or modifying operation of the system in response to the measured parameter.
In general, cost typically increases with the measurement precision of the sensor. Cost can limit the use of highly accurate sensors in price sensitive applications. Furthermore, there is substantial need for sensors that have low power usage for systems that are battery operated. Ideally, the sensing technology used in a temporarily powered application will not significantly reduce the operating time of the device. Moreover, a high percentage of battery-operated devices are portable devices comprising a small volume and low weight. Device portability can place further size and weight constraints on the sensor technology used. Thus, form factor, power dissipation, cost, and measurement accuracy are important criteria that are evaluated when selecting a sensor or measurement system for a specific application.